Micro-Electro-Mechanical Systems (MEMS) components are made of integrated mechanical and electrical elements, microfabricated on a common semiconductor or dielectric substrate. MEMS switches have many properties that make them ideal for switching broadband electrical signals. For example, they typically have very broad bandwidth due to their high ½π(RonCoff), which translates into lower insertion loss in the ON state and higher isolation in the OFF state. MEMS switches are also physically small, and they have reasonably fast switching speeds. They also tend to have very low distortion, typically much less than semiconductor switches.
One problem with MEMS switches is that their reliability is greatly reduced if they are switched in the presence of a high power signal. This is called “hot switching”. Typically MEMS switches must switch at lower than about 10 dBm of power if they are to maintain their reliability. One solution to this problem is to use a power diverter to divert power from a MEMS switch before it is switched. A power diverter is also a switch, but one that can reliably switch in the presence of a high power signal.
A power diverter is placed electrically upstream from a MEMS switch. When the power diverter is in its ON state, some or all of the signal power supplied to the MEMS switch is diverted from the MEMS switch, thereby allowing the MEMS switch to be switched in a lower power (or no power) state in which the reliability of the MEMS switch can be maintained. When the power diverter is in its OFF state, it ideally passes signals to the MEMS switch with no distortion, or with distortion comparable to the distortion in the MEMS switch. However, the distortion in most semiconductor-based power diverters makes this difficult to achieve.
By way of example, some exemplary semiconductor-based power diverters are disclosed in U.S. Pat. No. 6,884,950 B1 of Nicholson et al.